Improvement in unloading freight or merchandise



UNITED STATES PATENT OEEIcE.

ROBERT BRAGG, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN UNLOADING FREIGHT OR MERCHANDISE.

Specification forming part of Letters Patent N0. 38,725, dated June 2, 1863.

more particularly for unloading vessels; and

I do hereby declare that the following is a full, clear, and exact description of the same, reference bein ghad to the accompanying drawings, milking a part of this specification, in which- Figure l is a side sectional view of my invention, taken in the line m a7, Fig. 2; Fig. 2,

a plan or top view of the same; Fig. 3, a transverse section of the same, taken in the line y y, Fig. l.

Similar letters. of reference indicate corresponding parts in the several figures.

This invention consists in the employment or use of two endless chains, having ,crossbars attached to them and fitted over rollers or pulleys, which are secured to a plank or skid, the latter having guards attached to its sides and ways attached to either or both. of its surfaces, all being arranged as hereinafter fully set forth, whereby freight or merchandise may be moved with the greatest facility for loading and unloading vessels and for similar or analogous purposes.

To enable those skilled in the art to fully understand and construct my invention, I will proceed to describe it.

A represents a plank, which may be of any suitable dimensions, and having a guard or side strip, a, secured to each side of it, which project at equal distances from both sides of the plank, as shown in Fig. 3. To one or bot-l1 sides of the plank A there are secured by bolts b'two parallel ways, c c. These ways are of metal, and they may be constructed of angle-iron, one portion of each of which is bolted to the plank, while the other portion is in averlical position and serves as the way, as will be fully understood by referring to Fig. 3. In Figs. l and 3 the ways are represented as being secured to one side only of the plank. The object in having them attached to both sides is that either side of the plank may be used or the latter turned either side upward.

B B represent two endless chains, which work over rollers or pulleys d, which are keyed on suitable shafts, e e, at the ends of the plank A. The chains B B work between the ways c c and the guards or side strips, c a, and said chains have cross-barsf attached to them at suitable and equal distances apart. (See Figs. l and 2.)

From the above description it will be seen that if a box or package be placed on the ways c c, and the endless chains moved by turning the rollers or pulleys d at either end of the plank, the box or package will be moved or carried along in consequence of one of the cross-barsfcoming in contact with it.

The chains B B are entirely out of the way, being between the ways c c and the guards or side strips, a a., and are not subjected to any of the weight of thebox or package, the latter resting on the ways only and the crossbars f resting on the ways c c. The guards or side strips, a a, keep the box or package on the ways, and at the same time keep the bottom of the plank a freefrom the surface on which the device rests..

The invention may be used either in a horizontal position or inclined, so as to elevate or lower goods, as may be'required in loading or unloading vessels, and it may be applied in any convenient way, as circumstances may require. In loading or unloading vessels, for instance, one end may be passed through the port and the other made to reston a trestle on the wharf, or on the wharf itself, and the chains may be operated by any convenien power.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The plank A, having ways c c attached to one or both sides, in combination with the endless chains B B, connected by cross-bars f, arranged or applied to the plank substantially as and for the purpose herein set forth.

2. The guards or side strips, c c, applied to the plank A, when used in combination with the ways c c, endless chains B B, and crossbars f, as herein described.

ROBERT BRAGG. Witnesses:

J AMES RoLPH, JAMEs L. KING. 

